how to fix P0171 code in Volkswagen Golf Eighth Generation (2020-present)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the vehicle to cool if the engine has been running.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum pump, hose clamps.
• Inspect all vacuum lines and intake manifold gaskets for any cracks or disconnections.
• Use a vacuum pump to test hoses and connections.
• Replace any damaged hoses or gaskets.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, Torx screwdriver.
• Remove the MAF sensor from the air intake duct.
• Clean the sensor using MAF cleaner spray; do not touch the sensor with hands or tools.
• If cleaning does not resolve the issue, replace the MAF sensor with a new one.

4. Check Fuel System

• Tools Required: Fuel pressure gauge.
• Connect the fuel pressure gauge to the fuel rail.
• Start the engine and check the fuel pressure against manufacturer specifications (typically 50-60 psi for the Golf).
• If pressure is low, inspect the fuel pump and filter for blockage or failure and replace as necessary.

5. Inspect Fuel Injectors

• Tools Required: Multimeter, injector cleaner.
• Disconnect the fuel injector connectors and test for proper voltage and resistance using a multimeter.
• If any injectors are faulty, replace them.
• Clean the injectors using a fuel injector cleaner if operational.

6. Replace ECT Sensor (if necessary)

• Tools Required: Socket set, torque wrench.
• Locate the engine coolant temperature sensor on the engine block.
• Disconnect the wiring harness and remove the sensor.
• Install the new ECT sensor and torque to the manufacturer's specification.